package com.woniuxy.microsysserver.util;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class IpUtil {

        private static final String UNKNOWN = "unknown";
        private static final String LOCALHOST = "127.0.0.1";
        private static final String SEPARATOR = ",";

        public static String getIpAddr(HttpServletRequest request) {
            System.out.println(request);
            String ipAddress;
            try {
                ipAddress = request.getHeader("x-forwarded-for");
                if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                    ipAddress = request.getHeader("Proxy-Client-IP");
                }
                if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                    ipAddress = request.getHeader("WL-Proxy-Client-IP");
                }
                if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                    ipAddress = request.getRemoteAddr();
                    if (LOCALHOST.equals(ipAddress)) {
                        InetAddress inet = null;
                        try {
                            inet = InetAddress.getLocalHost();
                        } catch (UnknownHostException e) {
                            e.printStackTrace();
                        }
                        ipAddress = inet.getHostAddress();
                    }
                }
                // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
                // "***.***.***.***".length()
                if (ipAddress != null && ipAddress.length() > 15) {
                    if (ipAddress.indexOf(SEPARATOR) > 0) {
                        ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                    }
                }
            } catch (Exception e) {
                ipAddress = "";
            }
            return ipAddress;

    }
}
